The planet Pluto has been demoted to "small solar system bodies" like other comets by the International Astronomical Union as it doesn't satisfy the defination of a planet. This announcement came after a week when two more planets were discovered taking the total number of planets to 12. The tenth was discovered more than three years ago. However yesterday's declaration left the solar system with only eight planets. For now, membership will be restricted to the eight “classical” planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto has been disqualified under the new rules for a planet which says, “a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit.” Pluto's orbit overlaps the orbit of Neptune.